Documents pointing to plans for a four-door version of Mercedes-Benz' SLS AMG performance flagship have surfaced online this week, discovered by enthusiast website Autoblog.

Found on theGerman Patent and Trademark website, the documents appear to be the genuine article, showing a clever four-door solution for the SLS that combines the current coupe's gullwing doors with a smaller rear suicide or coach door, or pair of doors.

In this way, the design is similar in execution to the rear passenger doors of Mazda’s RX-8.

The patent documents indicate that Mercedes-Benz has a particular interest in keeping weight gain to a minimum and maintaining the vehicles structural rigidity - which will prove challenging, given the absence of a B-pillar.

If the drawings are to scale, a future four-door SLS could be a little tight on rear leg-room. Being patent documents, there is no information regarding the four-door's drivetrain or specifications.

In regular two-door and convertible form, the SLS AMG is powered by AMG's trusty 6.2 litre V8, producing 420kW and 650Nm of torque.

The 0-100km/h run is dispatched in just 3.8 seconds and top speed is electronically limted to 317km/h.

A seven-speed twin-clutch Speedshift DCT transaxle is mounted between the rear wheels and linked to the 6.2 litre V8 via a carbon fibre drive shaft.